Band saw guides and guards



March 18, 1958 w. F. ocENAsEK BAND SAW GUIDES AND GUARDS Original FiledOct. 5, 1950 6 Sheets-Sheet 1 March 18, 1958 w. F. ocENAsEK 2,827,085

BAND SAW GUIDES AND GUARDS original Filed oct. 5, 195o e sheets-sheet 2Il EY oRNEY INVENTOR March 18, 1958 F, OCENASEK 2,827,085

BAND SAW GUIDES AND GUARDS Original Filed Oct. 5, 1950 6 Sheets-Sheet 3March 18, 1958 w. F. ocENAsEK BAND SAW GUIDES AND GUARDS 6 Sheets-Sheet4 original Filed ooi. 5, 195o'y INVENTOR. ////am .Zabana Qfenm'e BY Z 9florfiey- March 18, 1958 w. F. ocENAsl-:K

BAND SAW GUIDES AND GUARDS Original Filed Oct.

6 Sheets-Sheet 5 March 18, 1958 w. F. ocr-:NASEK Y BAND SAW GUIDES ANDGUARDS 6 Sheets-Sheet 6 Original Filed Oct. 5, 1950 BAND SAW GUHDES ANDGUARDS William Ferdinand cenaselr, South Piaindeld, N. Il., assignor, bymesne assignments, to Rockwell Manufacturing Company, a corporation ofPennsylvania Original application @einher 5, i956, Serial No. ld.Divided and this application August 2li, 1953, Serial No. 375,363

8 Clm'ms. (Ci. E53- 159) This invention relates generally to improvedmeans for controlling the operation of a continuous or endless saw band.More particularly to improvements in guides for band saw blades and tothe protection aiforded by the improved guides to the machine operator.

This application is a division of my application Serial No. 188,616filed October 5, 1950, entitled Band `Sawing Machine, issued November30, 1954 as Patent No. 2,695,637.

A general object of the invention is to provide an improved band sawhaving greatly improved sawing accuracy and improved operating andsafety characteristics for more conveniently performing a wide varietyof sawing operations.

Another general object of the invention is to provide improved mechanismfor guiding the band saw blade in combination with mechanism to aordband saw guards.

Another object is to provide an improved band saw with various componentparts so arranged as to simplify the manufacture and reduce the cost ofthe improved mechanism.

Another object is to provide laminated guide members, for a band saw, soconstructed and disposed as to be individually Iadjustable for guidingdilerent sizes of saw bands, Without the necessity of removing theguides from the machine.

Another object is to provide an improved saw band guide and guard havinga thrust member positioned rearwardly of a pair of laminated guidemembers which are individually yadjustable to accommodate dierent widthsand thicknesses of saw bands.

Another object of the invention is to provide a guide and guardapparatus for a band saw machine, which is quickly and easily adjusted7toward or away from the workpiece.

Another object of the invention is to provide improved means for guidingand controlling the speed of operation of an endless saw band.

A further object of the invention is to provide improved supportingstructure for a band saw in combination with improved mechanism forguiding and driving an endless saw band.

Another object of the invention is to provide an improved variable speedtransmission mechanism that is operatively connected to drive theendless saw band of a band saw throughout a wide selection of speeds ina high or low range.

A further object of the invention is to provide improved means forpivotally supporting the worl; supporting table of a band saw includingmeans for frictionally retaining the table in predetermined adjustedposition.

A still further object of the invention is to provide an improved bandsawing machine arranged to afford the greatest possible convenience andilertibility performing a wide variety of sawing operations.

A further object of the invention is vto provide a mechanism of thischaracter which may be readily and cheaply 2,827,085 Patented Mar. 18,A1958 ECC manufactured, which is durable and efiicient in service, andextremely simple to operate.

According to this invention, a band sawing machine is provided with agenerally C-shaped supporting frame of an improved unit typeconstruction that is disposed to `support in vertically spacedrelationship a pair of guiding wheels about which is trained acontinuous or endless saw band. For guiding the saw band along a path ofstr-aight line movement, a pair of individually adjustable laminated sawguides are carried by the frame in vertically spaced position above andbelow a Work supporting table that is pivotally supported on the lowerforward portion of the frame. Power for driving the saw band at aselected rate of speed in a high or low range is transmitted from adriving motor by means of a variable speed transmission mechanism thatis operatively connected to drive one of the saw guiding wheels.

A full and detailed description of the machine will be found in myabovementioned Patent No. 2,695,637 entitled a Band Sawing Machine.Therefore, only so much of the description of the machine will be given1 erein `as is necessary to disclose my present invention.

The foregoing and other objects of this invention, which will becomemore fully apparent from the following detailed specification, settingforth the severa-l illustrative embodiments, may be achieved by theparticular apparatus lconstituting `an exemplifying embodiment of theinvention .that is depicted in and described in connection with theaccompanying drawings, in which:

Figure 1 is a view in left side elevation of a band sawing machine inwhich the invention is embodied in practical form, parts of the machineframe having been broken away to show more clearly the unit typeconstruction thereof;

Figure lA is a fragmentary sectional view along the line A-lA of Figurel;

Fig. 2 is a View in front elevation of the machine including thevariable speed driving transmission mechanisrn and having a part of thehousing for the range changing mechanism broken away to show a part ofthe driving mechanism for the lower saw guiding wheel;

Fig. 3 is an enlarged detailed view in horizontal sec- -tion through theelevating and clamping mechanism for the upper saw guide takenapproximately along the plane represented by the line 3-3 in Fig. 2;

Fig. 4 is a diagrammatic View of a modilied form of variable speedtransmission mechanism interconnecting the driving motor and the rangechanging mechanism;

Fig. 5 is an enlarged detailed view in front elevation of the upper andlower saw guides including a fragmentary representation in verticalsection of the work suportinfr table interposed therebetween and takenon a :a i y plane represented by the line 5-5 in Fig. 2;

Fig. 6 is an enlarged detaiied view in right side elevation of the upperand lower saw guides;

Fig. 7 is a plan view of the upper saw guide showing individuallyopposed guide plates in saw guiding enouter opposed guide plates inretracted position;

Fig. 9 is a .plan View similar to Fig, 7 showing only the innermostopposed guide plates in saw guiding engagement;

Fig. l() is an enlarged detailed View in front elevation of a pair ofadjustable saw guides of modiiied form;

Fig. 1l is an enlarged view in right side elevation of the modified formof saw guides;

Fig. 12 is a plan View of the upper modified form of saw guide taken ona plane represented by the line 12-12 in Fig. 10;

Fig. 13 isa plan view of the upper modiiied form of- Ving Machine.

Yvertically spaced relationship.

'of saw bands.

'normally horizontal position.

guide plates in i the range changing transmission mechanism taken on aplane represented by the line Y16-16 in Fig. l5;

Fig. l7ris an enlarged View in rightV side elevation of the lowerportion of the'machine and showing the modied, form .of ,speed changingtransmission mechanism shown in Fig. 4; and, t

Fig. ,'18 Vis Ya view in transverse vertical section of the tablesupport bracket andthe table clamping .mechanism taken on a planerepresented by the line'18-4-18 of Fig. 17.

Referring more specically vto the drawings, Figs. l and 2 thereofparticular show generally in side and front elevationia band sawingmachine that is fully de-V scribed in my Patent No. 2,695,637, entitledBand Saw- As Vshown in these views, it may be seen that the machinecomprises essentially a generally C- shaped supporting frame 31V of Yanimproved unit type construction that is disposed to rotatably supportupper and lower saw guiding wheels 32 and 33 respectively in The frame31defines an open throat 34 constituting a working zone throughV which aworkpiece'may be fed totheV forward runeof a continuous or endless sawband 35 trained about theV saw guiding wheels 32 and 33. n Y

VTo support a workpiece during a sawing operation, there is providedtoward the front central portion of the machine a normally horizontalwork supporting table 36' ycarried by the frame '31 lin position todefine the lower limit of the open throat 34 formed thereby and which isprovided with a slotted opening 37 `to permit verticalV movement of theforward stretch of the saw band 35.

Power for driving the saw band 35 at a selected rate of speed in a highor low range is derived from a motor 38VV mounted within the lowerhollow portion of the machine frame 31 and connected through a speedchanger 40 toV drive a range changing mechanism 41 which, in turn, is

connected to drive the lower saw guiding Wheel 33.

In order to guide and guard the saw band 35 in straight line movementthrough the open throat 34 constituting the working' zone, a pair oflaminated saw band guides 44 and 45 Vare carried by the supporting frame31 Vin ver-V tically spaced relationshipv above and below the worksupporting table 36 and areY disposed toV be individually` adjustable toaccommodate varying widths and thicknesses AsY shown in Figs'. 1, 17 and18, the work supporting table 36 is pivotally supported toward the.upper forward portion of the lower wheel support Vfor angular adjustmentthrough an arc of approximately 45 from a Y To'VY adjustably support thetable 36 for pivotal movement, Ya Vbracket 8913erpendicularlysecuredtothe underside of the table 35 is provided with an arcuate slot disposedto engage a pair otk-horizontal guide pins-91and 92 extending'outwardlyfromV aV flat vertical bearing surface 93l formedfon the side face of amounting plate 94 that extends upwardly from theupprer forward portionof the lowerwheel support 50. The horizontal guide pins 91Y and 92,Fig..17,`

are so spaced and located with reference to the arcuateV slot V90Y as toguide the table V36 for pivotalV adjustment aboutV an axis formed bythe'intersectio'n of the horizontal plane ,ofthe table surface andtheVertical plane of the saw band 35.Y i

normally retained in trictional guiding engagementwith Y the flatvertical bearing surface 93 kformed on the mounting plate 94 secured tothe lower wheel support 50 dur-Y Y ing pivotal adjustment of the Vtable36. To elect this result, a horizontally disposed stud 97 secured at itsinner end to the vertical mounting plate 94 and extending out- 164- otthe bracket and a locking member 105'thread-Y` edly securedV to theextreme outer end of the stud. With t the locking member in disengagedor unclamped po- .'36 is angularly adjusted, the table is apertured toreceive;

36 in manner to engage'the forward stretch of the saw;

sition, as shown in Fig., 18, therspring 9,8 is disposedto exertpressure between the member 105 and thebracket `face 164 in manner tourge the ilat bearing surface 96 Y formed on the inner side thereof intofrictional engagement with the vertical guiding surface 93 of themounting plate 94. The resilient force exerted by the spring 98 issuiiicient torretain'the table 36 in any selected vposition of Y angularadjustment without preventing a further manual adjustment thereof.

To clamp the table 36 iinmovably to the lower wheell support 54? in aselected position of angular adjustment, the clamping member 165 isoperative to engage a peripheral flange 196 integrally formed with thecup shaped washer 99 to urge the table bracket 89'into stationary`clamped engagement with the vertical mounting plate 94. Thus, the spring93 is protected against being fully compressed whenever the clamp member105 is moved into full clamped position because of the fact thateit isyfully enclosed within the outwardly extending peripheral flange 166 ofthe cup shaped washer 99.

To indicate theV degree ot'pivotal adjustment ofthe;

table 36,'.an indicating scale V107Secured to the table bracket 89 isprovided with indicia arranged to cooperate with a pointer 198 securedto the mounting plate 94.V To provide clearance for the saw band 35 asthe table a circular` plate 109,'Figs. l and 2, which is providedwith aslot corresponding to the table slot'37 for permitting vertical movementof the saw band. Y Y Y Y As shown in Figs. l and'2 the upper saw guideguard 44 and the lower saw guide 45 Vare respectively carriedV invertically spaced relationship toward the front or the machine by theupper and lower wheel supports 49 and 5t) and are positioned above andbelow the machine table band 35.- As shown in Figs. 2, 5 and 6V each ofthe saw lband guides 44 and 45 ris of generally similar `constructionand includesa support blocky disposedvto carry a pair of opposedlaminated C-shaped vguide menibers 111 and 112 for independentadjustment toward'or away from each other in manner to define va guidingslot of appropriate width and depth to accommodate the bandV saw blade35. To guide theV stretch 'of thelsaw band 35 extending betweenthe'guide members V44V and 45 lwith maximum rigidity for obtainingincreased accuracy in aj sawing operation, each of the pairs of opposedguide ele.-V

` outer end of1a horizontal rod V1717 slidably keyedfor later-` .ialadjustment in a bracket 11S carried a't-the lower end,

ments V111 and 112 constituting the upper and lower saw guides 44 and 45respectively,isprovided with a pair of inwardly Vopposed and verticallyspaced` saw band guiding edges 113 and`114 disposed in parallelisin.V j

The support block 110 of the lower guide member 451is secured to theouter end of a horizontal rod '1115'V slidably keyed for lateraladjustment in aborted hole" formed in the table mounting plate 94 towardthe vupper forward portionof the lower wheel support Stlandisiarrangedgto be clamped in predetermined adjusted posi; tion by means ofa clamp screw 116,:as shown'in Figs. 1 and 2. t Y

` The support block llrof the-upper saw guidefdfi is supported forlateralrand vertical adjustment at the aseaoee ably keyed in a bracket120 bolted directly to the upper wheel support 49. A clamp screw 123threaded in the upper bracket 120 is operatise to retain the verticalrod 119 in adjusted position and a clamp screw 124 threaded in the lowerbracket 118 is operative to retain the horizontal rod 117 in apredetermined position of lateral adjustment.

As shown in Figs. 2 and 3, resilient means operative in conjunction withthe clamp screw 123 whenever the clamp screw is in disengaged orunclarnped position are arranged to retain the vertical rod 119 inadjusted position without preventing further vertical adjustmentthereof. As there shown, the bracket 12d is provided with a horizontallybored hole 125 of reduced diameter that is axially concentric with athreaded hole disposed to receive the clamp screw 123. The clamp screw123 being of a reduced length disposed to extend only partially throughthe threaded hole formed in the bracket 12d, is provided at its innerend with an axially concentric bored hole arranged to slidably receivean extending pilot rod 127 of reduced diameter that is secured to aplunger 128 slidably carried for axial movement within the bored hole125 formed in the bracket 12%. The plunger 128 is provided with aV-shaped inner end that is disposed to engage a complementary V-shapedlongitudinal groove 129 formed in the vertical rod 119.

The plunger 128 is of stepped diameter, having its central portionencircled by a spring 130 that bears at one end against a shoulder 131formed on the plunger and at its other opposite end against the innerend of the clamp screw 123. With the clamp screw 123 in disengaged orunclamped position, as shown in Fig. 3, the spring 130 is disposed tourge the inner V-shaped end of the plunger 12S into frictionalengagement with the V-shaped groove 129 formed on the vertical rod 119in manner to restrain the rod against downward and pivotal movement.Although the resilient pressure exerted by the spring 130 is sufficientto maintain the rod 119 in vertically adjusted position, it is not greatenough to prevent or interfere with the manual vertical adjustmentthereof.

To elect a controlling vertical adjustment of the rod 119 for varyingthe height of the upper saw band guide 44 above the work table 36, asshown in Figs. l, 2 and 3, a pinion 133 journalled in the bracket toengage rack teeth 134 formed on the rod 119 is connected to be actuatedby means of a control handle 135 carried on the outer end of a pinionshaft 136.

To clamp the rod 119 securely to the bracket 12d in a stationaryposition of vertical adjustment, the clamp screw 123 is selectivelymovable to engage a shoulder 137 formed by the central portion of theplunger 138 in manner to urge the V-shaped inner end thereof intolocking engagement with the V-shaped groove 12.9 formed in the rod.

As shown in the enlarged views in Figs. 5 and 6, the lower saw bandguide 45 is so positioned that the converging narrowed ends of thelaminated guide members 111 and 112 carried by the support block 11@extend upwardly into a recess 133 formed in the underside of the table36. The upper saw band guide 44 is vertically adjustable in manner thatthe converging narrowed ends of the laminated guide members 111 and 112carried by the upper support block 110 are brought as close as possibleto the upper surface of a workpiece, for example, the workpiece 139carried by the table 36. Thus, the upper and lower saw guides 44 and 45are disposed to be positioned as close as possible to the opposite sidesof the workpiece 1%", carried by the table 3d in manner to guide the sawband 35 and restrain it against both rearward and lateral movementduring a sawing operation.

To accommodate varying thicknesses of workpieces, the height of theupper saw guide 44 above the table 36 may be regulated by means of thepinion control handle 135, as shown in Figs. 2 and 3. To permit maximumupward vertical movement of the upper guide 44 for accommodating anysize of workpiece that will pass through the open throat 34 constitutingthe working Zone, the upper wheel support 49 is provided at its lowerforward corner with a notched out recess 141, Fig. l, permittingcomplete retraction of the upper guide.

To enclose that portion of the saw band 35 between the upper saw guide44 and the upper wheel support 49 for aording continued protection to amachine operation, as shown in Figs. l and 2, there is provided avertical saw guard 142 disposed to extend upwardly from the upper sawguide support block 110. As shown in Figs. 7 and 8, the saw guard 142 iscarried for pivotal movement by a vertical pin 143 journalled in theupper block 110. This allows the saw guard 142 to be pivoted into aguarding position or into a parked position when the saw band is beingremoved from the saw guide 44. A thumb screw 144 threaded in the upperblock 110 of the guide 44 is provided to lock the saw guard 142 to thesupport block in guarding position. The movement of the saw guide guardblock 111i closer to or away from the workpiece eltects movement of thesaw guard 142 the same amount. At all times the saw band blade above theworkpiece is guarded to afford protection to the machine operator.

inasmuch as the saw guides 44 and 45 are of generally similarconstruction, only the upper guide 44 will be described in detail. Asshown in Figs. 5 and 6, the upper support block 111i is provided with alaterally otfset recess formed rearwardly of the central portion of thelaminated guide members 111 and 112 in manner to receive a rotatablethrust roller 145. The thrust roller 145 is journalled on a stub shaft146, carried towards one side of the block 11), for rotation in a planetransverse to the plane of the guiding slot formed by the opposedlaminated guide members 111 and 112 about an axis which is laterallyoiset therefrom. Thus, the saw band 35 threaded through the guiding slotdelined by the laminated guide members 111 and 112 is restrained againstrearward movement by having its rearward edge engage the forward sideface of the rotatable thrust roller 145 along a line that is laterallyoffset from the axis thereof.

Each of the opposed laminated guide members 111 and 112 of the upperguide member 44 is slidably carried for movement toward or away fromeach other in the same vertical plane on flat vertical bearing surfacesformed on the front face of the support block 110, as shown in Figs. 5,6 and 7. To limit the degree of lateral adjustment, each of thelaminated guide members 111 and 112 is provided with a pair ofhorizontally elongated slots 147 and 14S respectively arranged toreceive clamping bolts 149 and 156 which extend therethrough tothreadedly engage the support block and which are operative to clamp theguide members in a selected position of lateral adjustment.

in addition to being laterally adjustable for varying the width of theguiding slot to accommodate ditferent thickness of saw bands, theopposed laminated guide members 111 and 112 are individually adjustablein a manner to vary the depth of the guiding slot formed therebetweenfor accommodating different widths of saw bands, as shown in Figs. 7, 8and 9. To etfect this result, each of the laminated guide members 111and 112 is composed of a plurality of slidably superimposed individualguide plates of laminae 152, 153 and 154, formed in such a manner as topresent a C-shaped plate. The guide plates or laminae are provided witha pair of horizontally elongated guiding siots 147 and 14S, as shown inFig. 5, arranged to be engaged by the clamp bolts 149 and 150. Each ofthe individually opposed guide plates 152, 153 and 154 are provided witha pair of vertically spaced, inwardly opposed guiding edges 113 and 114disposed in parallelism and'perpendicular to the plane in which theguide plates are slidable.

Y VYguiding slot defined by VVtheopposed guide members `158 and E59.'Ihe thrust roller 164 is journalled on an axisV 111 and 112 are sopositioned that the vertically spaced bearing surfaces 113 and 114 ofeach guide plateia're inthe same plane to form continuous full depthYbearing surfaces for Vguiding the saw band. To provide a slot foraccommodating a saw band of intermediate Width, as shown in Fig. 8, theouter opposed guide plates 154 of the laminated guide members 111 andi12 are retracted from saw engaging position to leave ronly the innervopposed lguideplates V152 and 153 thereof in position to Ydefine Va'sawguiding slot. For guiding a narrow saw band, as shown in Fig. 9, both ofthe outer opposed guide plates 153 and 154 of the laminated members areretracted to leave only the innermost opposed guide plates `152 thereofin position Vto define a slot for guiding Y the saw band.V Y Y Y Y iVJim mydevice the straight line guiding `effect upon a saw band isextended over a longer length of a saw bandthan has been heretoforepossible and as a result the accuracy of a band saw machine has beenimproved. The frictionaliheat which would be engendered by the contactof a sclidrguiding member of the length of the f My device also aids inreducing saw band fatigue dueVV to bending stresses and to heatoccurring in the yarea of the greatest stresses. The bending stressesare those set up by the lateral liexure Vof a saw band and the rearwardbending force that is exerted upon saw bands by materials being actedupon. Thesev two stresses cooperate to develop cracks in a saw bandwhich start at the sawteeth root and extend inward into the band portionof the saw band. The additional factor of heat aggravates the eliects ofthe bending stresses. Itis therefore apparent that my guides for sawbands as disclosed herein2 tends toY relieve these conditions in amanner that has not been heretofore Vpp ssible. Y

' ln" aV modified form'of Aapparatus for guiding a saw band, as shown inFigs. 10'and llfthere are provided a pair of vertically spaced saw bandguides 155 and 156 respectively'carried by the laterally and verticallyad-V justableerod 117 and the laterally adjustable rod 115 in verticallyspaced positions above and below theY work supporting table 36. As thereshown, each of the saw band guides Y155 and 1,56 includes a supportingblock 157 provided with angularly converging guidewaysrespectivelypdisposedto support a pair of opposed laminated guidemembers 158 and 159 for slidable adjustable movement towards or awayfrom each other in the same plane."`Y` g Each ofthe opposed laminatedguide members 158 and 15,9 isn provided with an elongated slot V160disposed to receive a clamping screw 163 extending therethrough toVtlireadepdly 4engage the support blockV for clamping the Y guidemembers in predetermined adjusted position and for limiting Vthelongitudinal movement thereof.'

'Ifo' restrain the saw band35 threaded ,between the op- Y posedlaminated guide members 158 Vand 159 against upperV support block 157 ina position rearwardly of the lyin'gvin a VVplain-e approximatelyparallel tothe plane in wbi-chithe'guide members 158 and 1759 aremovable, for

, inav plane that angularly intersects .the verticalV plane of theguiding slot defined by the guide members.L

This arrangemntof the thrust bearing 164 llowsfo'r line contact of therear surface of the saw blade withV the periphery surface of the roller,Vkeeping the frictionY between them at a minimum.Y Y i Thus, theV sawband'35 restrained against lateral move.-Y

ment by the opposed laminated guide members 158 and i saw guide i535,however, I prefer to use a modified form using a thrust shoe in place ofa thrust roller,'as:` shown in Figs. l() and ll. Thev lower saw guide asshown, isl pro :led with a thrust shoe vcarriedv byY the- 'lower portblock 157 in aY position rearwardly Vof the4 laminated guide membersT153 and 159 in manner to engage the rearward edge of saw band 35.VA'saw band threaded through the upper saw guide 155 andthe lower 'sawguide 155, will be restrained against rearward. movement by therotatable thrust roller 164 carried by the upper support block 157, andby the lower support block 157. y t t t Each of the opposedlaminated'sawV guides SSj'andV 159 is composed of a plurality ofindividual .guide plates or laminae 66, 167 and 16S slidablysuperimposed upon each other for selective individual adjustmentinimanner to vary the depth of the guiding slot formed therebetween.'The separate guide plates 166, 16,7'and 168 are each provided with anelongated slot 160 disposed to be engaged by the clamping screws 163.and are arranged'to have their inner, angular ends disposed inparallelism and in a'planeV perpendicular to the plane in which the'guide plates are movable. As shown in Figs. l2, 13 and 14, the separateguide plates 166, 167 and Y16S,V constituting the opposed laminatedguide members 158 and 159 may be so positioned as to define a slot ofvaryingdepth for guiding a saw band of wide, intermediatefor narrowguide members from the supporting block...AV lv v Y Power for drivingthe saw band 35 at a selectedfspeedV in a high or a low range is derivedfrom themotor 38 which is carried for a relatively slight vertical'adjustment on a motor support plate .172 pivotally mounted within thehollow base .39 of the machine, as shown inFigs. l and 2. From amultiple grooved, steppe'didriving pulley 173 keyed to the motor. shaft,power is transmitted by means of a belt 174 to drivefa stepped pulleyA175 vrotatably journalled toward the outer end of an independentlyrotatable transmission'shaft 176 journalledinthe range width,respectively, without removingtthe guide plates Sora changing mechanism41, as shown in Figs'. 2 and 15. "The multiple grooved stepped pulleys173 and 175, together with the'power transmitting belt 174, areoperative in well known manner to constitute the selectively adjust-Vable stepped speed changer 40. I l'.

To facilitate the adjustment of the `belt 174 ahoutthe stepped pulleys173 and 175 for selectively"varying4 the Y which, in turn, electsupward'movement of the `driving- Y pulle 173 toward the driven pulley175 for facilitating the manual adjustment of the belt 174 about thepulleys.

To limit pivotal movement of the Ymotor plate 172, Vas well as toprovide'a proper driving tension Von thebelt i745, a'vertical stud 18@secured withintthetbase 39 is disposed to engage the outer end of themotor support Yplate'172. A pair of springsll and 182 carried bythe stud180 on the opposite sides of the motor'suppbrt plate V172 are operableto resilientlylimit the pivotal movement Y the thrust plate `m` he rangechanging mechanism 41 is contained within a housing 183 secured at itsinner side to a hollow cylindrical housing 18d integrally formed withand extending laterally outward from the lower wheel support Si) bymeans of cap screws 185, Fig. l5. The underside of the housing 133 issupported upon the upper surface of the hollow base 39 by means of ajackscrew 186 interposed therebetween.

The range changing mechanism 41 shown in Figs. 2 and l comprisesessentially a pair of clutches 187 and 18@ selectively actuatable totransmit power from the stepped driven pulley 175 to rotate the sawdriving transmission shaft 176 at a selected speed in a high or a lowrange. The saw driving transmission shaft 176 is journalled toward itsouter end to rotate in a bearing 139 carried by an outboard support 19t?bolted directly to the housing 183 and at its inner end in a pair ofaxially spaced bearings 192 and 123 carried within the circular housing184 secured to the lower wheel support Si?. At its extreme inner end,the transmission shaft 176 is provided with a slight taperiigcorresponding with a cornplementary tapered bore formed in the hub195 of the lower saw guiding and driving wheel 33. The lower guidingwheel 33 is keyed to the inner tapered end 194 of shaft 176 and securedthereto by means of a lock washer 196 and a cap screw 197 for rotationwithin the housinfT formed by the lower wheel support 59.

T he range changing clutches 187 and 183 respectively are provided withhollow circular outer housings 1&8 and 299 respectively connected to bedriven throughout high and low speed ranges. rthe high range clutchhousing 119 is provided with an outwardly extending, elongated hub 222integrally formed therewith and is journalled to rotate on the rightwardend of the transmission driving shaft 176 on sleeve bearings 293 and24M. For driving he rightward clutch housing 19? in a high range, theupper multiple groove pulley 17S is keyed directly to the elongated hub2122 integrally formed therewith.

"i" he clutch housing 19S of the low range clutch 137 is provided withan extending hub 205 of reduced diameter that is journalled to rotate onthe central portion of the transmission driving shaft 176, on sleevebearings 296 and 297. For transmitting power from the pulley 75 to drivethe clutch housing 193 at a reduced range of driving speeds, a pinion263 l-:eyed to the hub 2il2 of the rightward high range clutch housing199 is operatively connected to engage an enlarged spur gear 209 securedto a jaclcshaft 21@ which is, in turn, journalled to rotate in the lowerportion of the housing 183. A pinion 211 secured to the opposite end ofthe jackshaft 210 is disposed to engage gear teeth 2l?. formed on theperiphery of the low range clutch housing 1%.

To transmit power from the leftward clutch housing 1398 for driving thetransmission shaft 176 in the low range, an inner clutch element 21dkeyed to the shaft 176 is provided with driven clutch plates 215arranged to be engageable with driving clutch plates 216 slidably 1eyedat their outer periphery within the clutch housing 193. A cover plate227 secured to the clutch housing 1% by means of cap screws is threadedto receive a rotatable adjusting element 219 disposed to be retained inadjusted position by means of a lock screw 220. rToward its inner,forward portion, the adjusting element 219 is provided with an outwardlyinclined circular guideway 221 arranged to guide a plurality ofactuating balls 222, circumferentially spaced about the inner clutchelement 21d, for outward movement into wedging engagement with a clutchactuating plate 223 to effect driving engagement between the drivingclutch plates 216 and the driven lutch plates 215.

in a similar manner, the rightwara range clutch is provided with aplurality of driving clutch plates 225 and driven clutch plates 22oselectively engageable to transmit power from the outer clutch housing199 to drive the transmission shaft 176. A plurality of clutch i@actuating balls 227 are retained in circumferentially spa-:edrelationship about an inner clutch element 22S by an outwardly inclinedcirca 3 guideway formed at t inner beveled edge of a circular adjustingelement 2 carried in a clutch cover plate 231 Whenever the hi rangeclutch 138 is disengaged, as shown in Fig. l5.

To effect selective engagement of the clutch 137 or the clutch 18S,there is provided intermediately of the clutches an actuating sleeve 232slidably carried on the transmission shaft 176 for axial movement.Adjacent to its oppositeiy beveled ends, the actuating sleeve 232 isprovided with a pair of ball races 233 and 23d respectively disposed tobe engaged by the clutch actuating balls 222 or 227. As the sleeve 232is moved leftwardly to effect engagement of the low range clutch 187,the beveled or tapered leftward end thereof operates to move theactuating balls 222 outwardly to exert pressure between the angularlyinclined circular guideway 221 of the adjusting element 219 and theaxially slidable clutch actuating plate 223. With the sleeve 232 movedto its limit of leftward movement, the actuating balls 222 will beseated in the ball race 233, as shown in Fig. l5, in which position theballs will function in a manner similar to a detent mechanism forretaining the sleeve in its leftward position and thus maintaining theclutch plates 215 and 216 in driving engagement.

in a similar manner, the actuating sleeve 232 is axially movable to itsextreme rightward position to effect a driving engagement between theclutch plates 22S and 226 of the high range clutch 138. ln the eventneither of the clutches 137 and 18S is to be engaged, the actuatingsleeve 232 is movable to a central neutral position intermediately ofthe clutches, as shown in Fig. 2.

For effecting selective axial movement of the actuating sleeve 232 ineither direction from its neutral position, Fig. 2, to effect engagementof either the low range clutch 137 or the high range clutch 188, thereis journalled on the upper surface of the range changing housing 183 acontrol lever 235. The control lever 235 is secured to the outer end ofa vertical shaft 236 journalled to rotate in a support bracket 237secured to the upper surface of the housing. At its inner' end, as shownin Figs. l5 and 16, the vertical shaft 236 is provided with an eccentricarm 23S disposed to engage the upper end of a laterally pivotableshifter fork 239 pivotally carried between a pair of spaced arms 240 and241 depending from the underside of the bracket 237. The lower forkedend of the shifter fork 239 engages an annular groove 242 formed on thecentral portion of the axially slidable clutch actuating sleeve 232.

Referring now to Figs. 4 and 17, the modified form of a speed changingmechanism 244 there shown is interposed between the motor 38 and therange changing mechanism el for transmitting power therebetween to drivethe continuous saw band 3S throughout an infinitely variable selectionof speeds in a high and low range. T he infinitely variable speedchanging transmission mechanism 24d comprises essentially anintermediate pulley unit .2Q-S of the expansible variable pitch typerotatably carried toward the outer end of one arm 2da of a movable bellcrank 247 which, in turn, is pivotally supported by the machine base 39.A driving pulley 248 keyed to the shaft of the motor 33 and a drivenpulley 249 keyed to the outwardly extending hub 292 of the hub rangeclutch housing 199 are rotatable in a plane parallel to the plane ofrotation of the intermediate pulley unit 2435' and are interconnectedtherewith by means of a lower driving belt 251B and an upper drivingbelt 251, respectively.

The intermediate pulley unit 245 is provided with an axially floatingcenter section 252 which is slidably keyed on a pulley hub 253 formovement between a pair of fixed end sections 25d and 25S secured to theopposite ends thereof in well known manner. The lower driving belt 25@is trained about the lower motor pulley 24S and l1 a groove 256 ofvariable diameter formed between the axially floating center section 252and the leftward end section 254 of the'interrnediate pulley unit 245.En a similar manner, the upper driven belt 251 is trained about theupper pulley 249 and a groove 257 of variable diameter formed betweenthe movable center section 252 and the rightward end Vsection 255 of thepulley unit 245.- Bodily downward movement of the intermediate pulleyunit 245 operates in well known mannerthrough the action of thecooperating belts to effect` leftward movement of the axially movablecenter section 2i@ thereof to increase the effective driving diameter ofthe pulley groove 256 and to decrease the driving diameter of the groove257 for decreasing the rate of speed of the driven pulley 249.Conversely, upward movement of the intermediate pulley unit 245 operatesthrough the action of'the cooperating belts to increase `thekspeed ofthe driven pulley 249.

To eiect selective upwardror downward movement of the intermediatepulley unit 245, the bell crank 247 is pilot 258 secured Ytoa travelingadjusting nut 259 threaded on the inner end of an adjusting screw 269.The

adjusting screw 26.6 is journalled to rotate in an extending arm 261securedV tothe machine'base 39 and is provided at its outer end with ahandwheel 262 which is operative to rotate the shaft for effectingselective longitudinal movement of the adjusting nut 259 'in manner tomove theY bell crank for eifecting'upward or downward bodily'movement ofthe intermediate pulley unit 245. y

From the foregoing description and explanation of the construction andoperation of the saw guide and guard herein set forth as exemplifyingthe invention, it is apparent that there has beenprovided an improved,eco'- nomically constructed and simple operating unit type saw guide andguard. Although the invention has herein been described in detail forthe purpose of setting forth a practical apparatus, it is to beunderstood that the particular device is intended to be illustrativeVonly and that Ythe various inventive features may be incorporated inother structural forms and may be applied to other types 'of `machineswithout departing rfrom the spirit and scope of the invention as denedin the subjoined claims.

The principles of the invention having now been fully explained inconnection with the foregoing` description of embodying structure, Ihereby claim as my invention:

l. In a -band sawing machine, a frame including a substantiallyrectangular upper wheel support having a peripheral flange, an upper sawguiding wheel rotatably carried by said support within the protectiveilange formed therewith, a cover hinged torsaid support in a manner tocooperate therewith to constitute a hollow protec- Ative enclosure forsaid wheel, said wheel support being providedin its Vlower peripheraltlange `with a pair of spaced apart openings adapted to receive therearward and forwardstretches of a'saw band trained about said wheel, alower sawguiding wheel journalled in said frame A justably carried bysaid support block for selective horizontal movement therewith intoguiding engagement with the forwardrstretchV of said saw band, anupwardly'extending guard pivotably supported by said support blocksupport block for clamping saidV guard member in its guarding positionencompassing the cutting edge of said saw band, said guardmemberextending upwardly within the front opening formed in the lowerperipheral ilangeV of said upper wheel support and cooperating with saidupper wheel support and said-cover to enclose the cuttingv edge of theupper portion of the forward stretch of said saw band extendingtangentially downward from said upper saw guiding wheel, said guard andsaid guide means being vertically movable upon vertical movement ofrsaidguide rod, said guard and said guide means being transversely movablerelativeV to said guide rod, Vand clamping means respectively connectedto clamp said guide rod inV a selected position of vertical adjustmentand to clamp said support rod in a selected position of horizontaladjustment.

2'. ln a band sawing machine, a frame, an upper wheel housing carried bysaid frame and comprising a at support plate integrally formed with aperpendicularly extending peripheral ange, a pair of spaced apartopenings formed in the lower flange presented by said rhousing toenclosethe forward and return stretches of a saw band, an upper saw guidingwheel journalled within the partial enclosure constituted by said hangedhousing7 a depending support block movably suspended beneath saidhousing for a selective Vertical and horizontal position- Y ingmovement, adjustable saw guide means carried by said support block, anupwardly extendingV saw guard pivotably secured to the upper surface ofsaid support block for pivotal movement about a vertical axis into sawguarding position, said guard being disposed to telescope upwardlywithin the one of the ange openings Y'presented by said housing toenclose the forward stretch of a saw band extending tangenti'allydownward from `said upper saw guiding wheel, and aV hinged coversecuredV to said housing to cooperatetherewith to form a protectiveenclosure for said saw guiding wheel and in a manner that said saw guardis constrained by said cover against pivotal movement out of sawVguarding the cover is closed. V

3. In an apparatus for eecting vertical adjustment of a saw band guide,a vertical guide-rod having rack teethand presenting a longitudinalgroove, a carrier disposed to slidably support said'guide rod forvertical adjustment, a pinion journalled in said carrier disposed toengage the said rack teeth formed Von said guide Vrod and arranged tobe. rotatable for effecting a selective vertical V adjustment of saidYguide rod, a guide shoe movably carried by said carrier disposed tonormally engage the` said groove in said guide rod in a manner toprevent rotational movement thereof, a clamp elementmovably supported bysaid carrier disposed to operatively engage for pivotable movement aboutan axis parallel to the k forward bandV saw stretch for movement betweenan inoperative position anda guardingYposit-ion to encompass the-cuttingedgeof said Vsaw bandfmeans carried bysaidl said guide shoe, said clampelement being operable Yto urge said guide shoe into locking engagementwith said guide rod in a Vmanner to retain said guide rod in astationary non-movable position relative to said carrier,

resilientrmeans 4interconnecting said clamp element and said guideVshoerin a manner to exert Ysufficient frictional braking actiontherebetweento retain said guide'rod in vertically adjusted position andto permit a further' Vstraight stretch'of a saw band guided byA saidguide means, said pvotable guard being lhorizontally movableV with saidsupport block, and separate clamping means respectively connected'toclamp said horizontalY rod in a Y position when selected position ofhorizontal adjustment and to clamp said guard in guarding positionwhereby both said guard and said guide are positionable conjointly bymovement of said support block.

4. In a band saw having a pair of saw band guiding Wheels journalledabout spaced parallel axes and a continuous saw band entrained over saidwheels, a saw band guide, a support for said guide, means mounting saidsupport for rectilinear movement both in the direction of movement ofand in a path normal to the direction of movement of the saw band in theplane of its forward stretch between said wheels, and a guard mounted onsaid support and extending from and movable with said guide toward oneof said guide wheels whereby the portion of the forward stretch of saidsaw band between said one wheel and said guide is closely guardedirrespective of the adjusted position of said guide.

5. In a band saw having upper and lower saw band guiding wheelsjournalled about vertically spaced parallel axes in vertically spacedhollow housing portions deining a work receiving throat therebetween anda continuous saw band entrained over said wheels, said housing portionseach including a movable part which may be moved from its normalposition relative to the remainder thereof enclosing the wheel thereinto permit installation or removal of said band, an upper saw band guide,a support for said guide, means mounting said support on said remainderof the upper of said housing portions for vertical and horizontalmovement in a path parallel to the plane of the forward stretch of saidsaw band and a guard pivotally mounted about a vertical axis on saidguide support in interlocking relation with said upper housing portionremainder and said upper housing portion movable part when in its normalposition whereby the portion of the forward stretch of said band abovesaid guide is closely guarded irrespective of the adjusted vertical orhorizontal position of said guide so long as the movable part of theupper housing portion is in its normal position.

6. In a band saw having upper and lower saw band guiding wheelsjournalled about vertically spaced parallel axes in vertical spacedhollow housing portions detining a work receiving throat therebetweenand a continuous saw band entraned over said wheels, said housingportions each including a movable part which may be removed from itsnormal position relative to the remainder thereof to permit installationand removal of said band, an upper saw band guide, a support for saidguide, means mounting said support for vertical movement in a pathparallel to the plane of the forward stretch of said saw band, and aguard pivotally mounted on said support for movement about a verticalaxis from and to a blade guarding position and extending upwardly fromsaid guide into the upper of said housing portions where the partsthereof unite when the movable part is in normal position whereby theportion of the forward stretch of said band is guarded irrespective ofthe adjusted vertical position of said guide so long as said upperhousing portion part is in its normal position.

7. The combination defined in claim 4 wherein said guide comprises apair of laminated guide members disposed in parallelism carried by saidguide support and arranged to be so positionable that the opposed edgesthereof operate to form a slot for guiding the forward stretch of saidsaw band, an equal number of slidably superimposed laminae constitutingeach of said 1aminated guide members and disposed on said guide supportto be separately adjustable in a manner that the thickness of theopposed blade engaging edges of said guide members may be selectivelyVaried to accommodate saw blades of varying Widths, means for guidingsaid laminae during adjustment, and means for securing said guidemembers to said guide support in a selected position of adjustment.

8. The combination deiined in claim 7 wherein each of said laminae isformed with a pair of coplanar saw guiding surfaces separated by aninterconnecting portion terminating in an edge disposed in assemblyoutwardly from the saw blade relative to said coplanar surfaces wherebythe path of movement of the saw blade is guided over a substantiallength to assure accuracy in cutting with minimum surface contactbetween the guide and blade to prevent overheating of the blade.

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